The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
A conventional electrical cable generally includes a bundle of insulated wires/conductors and an insulating layer surrounding and binding the insulated conductors, thereby forming a core assembly. The core assembly may be further surrounded by a protective jacket or armor wires to provide mechanical strength to the core assembly.
The insulating layer that surrounds the bundle of insulated conductors must fill in the interstitial openings defined between the insulated conductors to prevent air or other gases trapped therein, which may be ionized by an electrical field during use and thus impair the performance of the electrical cable. Additionally, the insulating layer is generally formed of a material having the properties of incompressibility, wear resistance, and heat-resistance in order to protect the insulated conductors therein during manufacturing and use.
A conventional method of manufacturing the electrical cable requires a step of applying an insulating material around the insulated conductors in a liquid form to allow the insulating material to flow into and fill the interstitial openings to form the insulating layer. A helical tape is then wrapped around the bundle of insulated conductors and the insulating material to hold the same in place when the insulating material is still wet until a further manufacturing process that solidifies the insulating material is performed. After the insulating material is solidified to form a solid insulating layer, the tape serves no function in the completed core assembly.
The use of a tape in the cabling process has some disadvantages. First of all, the tape increases manufacturing cost and serves no substantial function to the completed electrical cable, except as a manufacturing aid. Second, wrapping the tape is burdensome and time consuming, thereby prolonging the manufacturing process. Third, improper wrapping of the tape may introduce undesirable stress to and damage the insulated conductors enclosed therein. Finally, the tape itself may be susceptible to hydrolysis in water at temperature above about 80° C.